The reaction of pyrimidine and pyrrolo(2,3-d)pyrimidine nucleoside derived organopalladium intermediates with olefins will be examined. The resulting nucleoside analogs are of interest for enzyme studies and as potentially biologically active compounds. Investigation at the nucleoside level will be concentrated on the coupling of allylic chlorides and fluoroolefins to the C-5 position of 2'-deoxyuridine. Derivatives of 2':deoxyuridine substituted at C-5 by fluorinated two and three carbon side chains will be tested for antiviral activity, cytotoxicity and as an antagonist for enzymes in the bio-synthetic pathway to 2'-deoxythymidine 5'-monophosphate. The reaction of mercurated poly(U) and poly(C) with lithium palladium chloride and allylic chlorides will be examined in detail. The synthesis of polynucleotides substituted at C-5 by aliphatic side chain terminating in the amino group is our primary synthetic target. Once achieved, methods for transforming the amino function to useful affinity labels and reporter groups will be investigated. Reactions which can be applied with a high degrees of selectivity at the polynucleotide level will be studied. A series of tubercidin 5'-diphosphate, 5'-Triphosphate, and 3',5-monophosphate derivatives substituted at C-5 will be prepare in order to probe the active-site specificity of enzymes utilizing ADP, ATP, cAMP as substrates and cofactors. Binding studies will be carried out on such key enzymes as cAMP-dependent protein kinase, pyruvate kinase, phosphoglycerate kinase, hexokinase and phosphofructokinase. New synthetic routes to modified nucleosides structurally resembling coformycin will be investigated. Routes for expansion of the heterocyclic rings of 2'-deoxyuridine and inosine are to be examined.